Dutch Slough Tidal Restoration Project
The Dutch Slough Tidal Marsh Restoration Project is the first major tidal wetlands restoration site in the Sacramento-San Joaquin Delta to be implemented by DWR. The project will transform 1,187 acres of land into tidal marsh to provide habitat for salmon and other native fish and wildlife.
The project is also part of California EcoRestore, an initiative to coordinate and advance at least 30,000 acres of critical habitat restoration in the Delta by 2020.
The project has three main goals:
Benefit native species by re-establishing a natural ecological network, especially for Delta species currently in decline
Contribute to scientific understanding of ecological restoration in the Delta
Provide shoreline access, education, and recreational opportunities
The Dutch Slough Project is located on the west Delta, within Oakley, a city with a population over 40,000 in Contra Costa County. It contains three parcels located on the western edge of the Delta.
Construction on two of the parcels, Emerson and Gilbert, started in May 2018 and is expected to be completed in 2019, followed by revegetation planting. Restoration of the third parcel, Burroughs, would begin in 2020.
How it works:
Dutch Slough currently sits along a high-grade slope, with site elevations ranging from six feet above sea level to six feet below sea level. In May 2018, DWR began smoothing the grade of that slope by excavating soil from higher elevations and moving it to lower elevations. Once the grading and channel excavation are complete, DWR will plant native plants, including about 50,000 tule plugs. Following two years of plant growth, in approximately 2021, DWR will breach the levees, allowing water from the Delta channels to flow in and out with the daily tides. Ultimately the project will reestablish a tidal marsh, creating a rich habitat for fish and wildlife.
The Dutch Slough project will be the Delta’s largest restored fresh water tidal marsh. The tidal marsh is designed to create conditions that will favor native aquatic species over non-native fishes such as largemouth bass. Young salmon will be able to hide from predators in the marsh at high tide. Scientists expect that the tidal marsh will provide rearing habitat where the young salmon can grow strong before they journey to the ocean, boosting their survival rates.
The Dutch Slough project preserves Native American heritage sites and protects one of the last remaining vineyards growing in a Delta sand dune. The vineyard is close to a century old.
Creating recreation and education:
Fifty-five acres of the south-central portion of Dutch Slough will be developed by the City of Oakley into a community park. The restoration project will enhance park amenities by including biking and walking trails, plus shoreline and fishing access. It will also feature interpretive signs to educate visiting school and community groups about Dutch Slough’s human history and marsh ecosystems.
The Dutch Slough project began in 2003, when DWR bought the property for $28 million. Before that, Contra Costa County planned to convert the pasture land – home to cattle grazing and dairy operations – into a housing development. The project is 15 years in the making, following a long approval process by a variety of federal, state and local agencies.
The Dutch Slough Tidal Marsh Restoration Project is part of the DWR Delta Levees Program, which funds levee improvements and projects that preserve and restore habitats in the Delta. It is also a part of the State Ecosystem Restoration Program, a multi-agency endeavor to enhance ecological function across the greater Delta.
Dutch Slough has been supported and/or funded by:
- California EcoRestore
- The U.S. Environmental Protection Agency
- U.S. Fish and Wildlife Service
- State Coastal Conservancy
- California Department of Fish and Wildlife (CDFW)
- The City of Oakley
- Contra Costa Water District
- The Delta Conservancy
- Natural Heritage Institute
- American Rivers
- Reclamation District 2137
Reports & Publications
- Dutch Slough Adaptive Management Plan Version 1.0, January 2008 (PDF: 7.27 MB)
- Dutch Slough Conceptual Plan and Feasibility Report, May 2006
- Dutch Slough Revised Conceptual Plan, October 2010
- Final Supplemental Environmental Impact Report: Dutch Slough Tidal Marsh Restoration Project, September 2014 (PDF: 26.93MB)
2014 Comments and Responses to Comments on Draft Supplemental EIR / EIS
The Dutch Slough site is located in the City of Oakley, eastern Contra Costa County, in the western Delta. The site encompasses 1,178-acres, and is bound by Dutch Slough on the north, Marsh Creek on the west, the Contra Costa Canal on the south, and Jersey Island Road on the east. The site comprises three parcels, partially separated by Emerson Slough and Little Dutch Slough.